Regenerative furnace



I(No Model.) M. WANNER.

REGENERATIVE FURNAGE.

Patented Apr. `10, 1894.

LII

Yllllllli D U U l HHHIIIIIIIE w- 44o ATTORNEY PATENT OFFICE.

MARTIN IVANNER, OF DENVER, COLORADO, ASSIGNOR OF ELEVEN-TWEN- .TIETHS TOWILLIAM B. CRITTENDEN AND JOHN M. MILLMAN, OF BU- oYRUs, oI-uo.

REG EN ERATIVE `FU RNAC E.

, SPECIFICATION forming part of Letters Patent No. 517,991, dated April10, 1894. l Application filed December 8, 1892. -Serial No. 454,457. (Nomodel.)

To all whom t may concern/.-

Be it known that I, MARTIN WANNER, a citizen of the United States, and aresident 0f Denver, in the county of Arapahoe and State of Colorado,have inventedcertain new and it a brief statement will be given of theresults which I accomplish by my invention whereby it will be morereadily understood and its advantages appreciated.

The improved furnace covered in and by this application is designed todo a variety of Work from the remelting of lead, type-metal, or anyother work requiring comparatively 10W temperatures, to the fusion ofbrass, copper, iron,'&'c., and the reduction of ores of all kindsrequiring high temperatures. It is not intended for anyspecifc purpose,nor is it exclusively a smelting furnace, but can be used not only forhigh and low temperature Work as above stated, but also for the burningof brick, terra cotta or porcelain, simply by changing the hearth, whichin my invention is easily effected because my hearth vis made adjustableand may be set either high or low in the combustion chamber as thenature of the work to be performed requires. And also the position andcomposition of my hearth may be changed depending upon the diierentkinds of work which the furnace is to perform. Furthermore, by simplyregulating the air inlet valves the nature of the flame may be instantlychanged from oxidizing to neutral or reducing, or vice versa. This isone of the reasons Why my furnace is capable of performing such avariety of work. Forinstance, supposing the furnace to be used forconverting pig-iron, containing phosphorus into steel the adjustablehearth would be constructed out of material with which the phosphorus inthe iron would combine, while an oxidizing flame would be used to removeexcess of carbon. It is self-evident that the two processes may needexposures to the action of the oxidizing iiame and to that of the hearthmaterial for dierent periods of time,

consequently it becomes imperative that either the action of the hearthmaterial or the action of the flame should be under the control of thooperator, this is effected with the air inlet regulators or valves.Again, the vertical position of the hearth in the furnace alsodetermines the action of the llame Whether oxidizing or reducing. Toillustrate: The hearth being placed near o r about level with theentrance ports of the air and gas, the free carbon in the flame producesa reducing action, while if the hearth is more elevated, the free oxygencomposing the outside of the flame, produces the oxidizing actionon thematerial on thehearth.

In my furnace the gas and air currents intercept each other and arethoroughly mixed before entrance into the combustion chamber proper, andthe air supply is regulated absolutely` according to the' amount of gasconsumed and the nature of the iiame required, by the air inletregulating valves, and my construction aims to bring about as nearly aspossible an even distribution of heat throughout the entire interior ofthe .combustion chamber and I do not as in some other furnacesconcentrate the maximum temperature at any certain point in thecombustion chamber, the uniform distribution of the heat throughout thecombustion chamber is desirable in any event, and for some of theoperations which my furnace is capable of performing it isindispensable, and one of the special objects of my construction is toachieve that result. The spaces outside of the bridge wall and withintheoutside Wall of my furnace are preferably not annular spaces but shouldmore properly be called cellular brickwork forming checkers or staggersand are, preferably but not necessarily, bound into and form part of thesolid brickwork, so that the whole of the furnace is one practicallysolid piece ot' masonry capable of working without any outside metalliccasing.

The invention consists, broadly stated, in so constructing the furnace,that it shall have a bridge Wall of refractory material, which entirelysurrounds the sides of the combustion chamber, and outside of the bridgewall there is an annular chamber or chambers IOG which preferably butnot necessarilysurround the combustion chamber in which chamber orVchambers, air is admitted from the outside, which in its passage to thecombustion chamber becomes heated by radiation from the bridge wall, andalso to a certain extent `by contact with the outer shell thereof, andthe products of combustion in my furnace are taken 0E at the upperportion of the combustion chamber and passing over the upper edge of thebridge wall and its outer shell are carried downward to the stackthrough another chamber or chambers which likewise preferably althoughnot necessarily entirely surround the exterior sides of the outer shellof the bridge wall. In all of these chambers, i. e., the ones in whichthe incoming air is heated, and those in which the products ofcombustion circulate on their way from the combustion chamber to thestack, I prefer to employ checkers, preferably staggered in theirarrangement, which create eddies in the flow of both the air and theproducts of combusiion, whereby the heat is better utilized in a mannerwell known.

Another feature of my invention is the ease with which the flame can beregulated or modified from an oxidizing to a reducing or neutral flame,or vice Versa, by means of regulating valves which control the airinlets in conjunction with my peculiarly constructed hearth. The bridgewall is very considerably contracted or drawn together, at the lower endof the combustion chamber, il. e., at the place where the incoming gasand air enter the combustionchamber,sothattheexpansionof these twoelements, which results upon perfect ignitionaud combustion, does notand cannot take place excepting within the combustion chamber itself. Imake the bottom of the combustion chamber or hearth separate anddistinct from the rest of the structure, that is to say, I construct itof brick, clay, tile, or other refractory material and in such mannerthat it is not interlocked with, or dovetailed into, the adjacentstructure of the furnace, but ontthe contrary so that it may bevertically adjusted relative to the combustion chamber and also easilyremoved when it is desired to modify either its shape or the compositionof which its upper part is constructed.

` I support this independent bottom upon its own proper supports whichcan be removed without endangering the rest of the structure, and theyare suitably made to secure the vertical adjustment mentioned.

In the drawings hereofz-Figure 1,is a ver tical section of my furnace onthe line an, x, of Fig. 2. Fig. 2, is a plan in section on the line y,y, of Fig. l. Fig. 3, is a plan View of the furnace; Fig. 4, anelevation of the furnace.

A, is the combustion chamber.V

B, is the bridgewall made of refractory material.

B is an annular outer shell of the bridge,

.wallg C is a space or chamber between the said bridge wall and outershell in which the incoming air which enters at D, D, the., afterpassing through the air Valve Q, Q, is heated.

E, is a chamber on the outside of the shell Bf of the bridge wall,through which the products of combustion pass on their way to the stack,shown at F (see Figs. 2, 3 and 4).

G, G, are fines or openings in the upper part of the combustion chamberabove the bridge wall as shown, through which the products of combustionpass from the combustion chamber to the space or chamber E. The flues G,G, are separate as shown so that the partitions between them may serveas supports for the snperposed cover J.

Il is an exterior wall whereby the chamber or chambers E, are formed.

I is a metallic shell, which I prefer to employ on the outside of allfor additional protection.

.I is a top for the structure upon which is supported the cover K. j

L, L are suitable passages through which the gas enters which dischargeat such points as to intercept the incoming hot air before entering thecombustion chamber to insure their thorough mixture.

M, M, &c., are suitable legs or supports upon which the furnace properrests: there may be as many of them as desired and of any preferredconstruction.

N is a central leg or support for the independent furnace bottom, O.This independent bottom, O, is as above stated made separate anddistinct from the rest of the structure, and the leg or support, N, isdirectly beneath it and is so constructed that when desired to renew thefurnace bottom, O, or to change its shape or composition, or to elevateor depress it, by proper manipulation of the leg or support the desiredresult may be readily attained. I illustrate the independent bottoni assupported upon a removable iron leg provided with a screw which can berun up or down as desired. This is a good form of support but may besubstituted by one of any other preferred construction.

It will be noticed that the lower portion of the bridge wall iscontracted or drawn in forming the narrow opening or throat, as at P, P,so that the air which follows the direction indicated by the arrowsmeets the gas passing upwardly through the passages, L, L, by the sideof the independent bottom in the narrow or contracted chambers or partsthrough which the hot air enters and below the combustion chamber, andthat immediately above the contraction of the bottom of the combustionchamber the bridgewall flares or widens out again to the normal 'widthof its interior, consequently there is provided immediately adjacent tothe contracted throat, but within the combustion chamber, an enlargementof the space occupied by the gas and air, so that they have ample roomwithin which to expand as complete combustion takes place and are notsubjected to any IOO compression, which would measurably interfere withcombustion, this consequently permits of as high a temperature -being atthat point, i. e., thus low in the combustion chamber, as well as aboveit.

Q, Q, are air valves set in the induction air pipes which connect withthe chamber or chambers C at the bridge wall, where by the supply ofoxygen may be regulated, absolutely, according to the nature of theflame required to accomplish the special .results de.- sired. l Theoperation of the furnace has been already indicated in the foregoing,and it is only necessary to suggest that in starting the furnace, thecover, K, is first removed, then the air valves, Q, Q, are opened, thona rag saturated with oil, or other means of ignition, is dropped inthrough the'open door K, then the gas is turned on which is immediatelyignited, thereupon the cover is replaced and the furnace runs itself thegas and air supi plies being properly regulated, until the nec- Fig. l),for drawing off the products; (not essary temperature is attainedpreparatory to charging the furnace, thereupon the cover,

K, is again removed and the charge, whatever it may be, is introduced.

t It will be noticed that my furnace is adapted to the performance ofvarious kinds of work, necessitating, however, certain changes in theform or composition of the independent bottom, that is to say, for asmelting or glass furnace a concave bottom, as shown, may be employed,the bottom, of course, being supplied with the usual duct or ducts (asshown in shown). For a heating furnace, a flat upper surface, or oneonly slightly concave may be given to the independent bottom; and forcrucible heating, tile or terra cotta and the like work a perfectly flator table form may be used, also the composition of the su rface of thehearth may be changed when itis to have a reactive effect on the charge.Also my hearth can be vertically adjusted relative to the combustionchamber for the purpose stated.

I call special attention to certain peculiarities in the construction ofmy furnace, which I believe have never been employed before, that is tosay, in other furnaces the bridge wall has been located between thespace or chamber `in which the ignition of the gases takes place and thecombustion or work-doing chamber, and it has had the effect not only ofreducing the available work doing energy of the flame, a portion of itbeing dissipated in the combustion chamber before entering the workdoing chamber, but also the bridge walls as ordinarily constructed areobstructions or deiiectors, over which the flame had topass to get tothe chamber in which the work was done, therefore, there was not only areduction of available heat but also a checking or compressing effectproduced upon' the flame, between the space or chamber in whichcombustion first takes place, and the chamber in which the work is done;moreover the deflection stated teided to throw the flame in the firstinstance against the roof or arch of the furnacewhich consequently isexposed to the most intense heat and its maximum energy is consequentlynot only lost, but brings about in a comparatively 'short time thedestruction of the arch, whereas in my furnace, all the energy is'expended -in the work doing chamber and in direct contact with thecharge and instead of there being any obstruction or wall or contractingor compressing effect, there is an .immediate expansion or enlargementof the space, so that there is no hinderance whatsoever to the instantand complete `combustion of the fuel; and my bridge wall g furthermoreunder my preferred construction entirely surrounds the sides of thecombustion chamber, which Ialso believe to be a new feature, so that allthe heat is retained and the working part of the furnace is protectedfrom radiation, and such radiation as does take place is utilized in theheating of the incoming air. To these peculiar features together withthose above stated I attribute the results which I secure, which aremuch more satisfactory than those secured by any other furnace known tome; that is to say, I can and habitually do, attain and maintain anygiven temperature practically uniform throughout the combustion chamber,using about twentyfive per cent. less fuel than in any otherconstruction of furnace known to me; also my furnace is perfectlynoiseless, because I have no obstructing bridge wall, which in otherfurnaces occasions a rapid succession of percussive ignitions of therapidly expanding air and gases Within the combustion chamber orwork-doing part of the furnace. Also my furnace by very slight andinexpensive alterations or modifications can be adapted to a greatvariety of work.

I do not limit myself to the details of construction shown anddescribed, since they may be somewhat departed from and stilltheessential features of my invention be employed.

I claiml. Thegcombination in a regenerative furnace of abridge wallentirely surrounding the sides of the combustion chamber, a chamberoutside of the bridge wall connecting with the external air and openingat the lower end of the combustion chamber, inlets for gas, also openingat or below the lower end of the combustion chamber, and a hearthadapted to carry the charge, substantially as set forth.

2. The combination in a regenerativefurnace of a bridge wall entirelysurrounding the sides of the combustion chamber, a chamber which'surrounds the bridge Wall, and which connects with the'external air andopens at the lower end of the combustion chamber, inlets for gas,opening at or below the end of the com-bustion chamber, and ahearthadapted to carry the charge, substantially as set forth.

3. The combination in a regenerative furnace of a bridge wall entirelysurrounding the sides of the combustion chamber, a chamber IOO IIO

around thebridge wall, connecting with the external air and opening atthe lower end of the combustion chamber, an independent chamber outsideot' the air chamber connecting with the upper end of the combustionchamber, through which the products of combustion pass on their way tothe stack inlets for gas opening at or below the lower end of thecombustion chamber, and ahearth adapted to carry the charge,substantially as set forth.

4. The combination in a regenerative furnace of abridge wall entirelysurrounding the sides of the combustion chamber, a chamber on each sideof the bridge wall across which projections extend from the side wallsto the opposite wall, whereby the structure is braced and supportedwithout interfering with the independent expansion ot' the two sides ofthe said chamber, said chamber or chambers connecting with the externalair and opening at or below the lower end of the combustion chamber, andinlets for the gas, opening at or below the lower end of the combustionchamber, substantially as set forth.

5. The combination in a regenerative furnace of a combustion chamber,contracted at its lower end, a bridge wall which entirely surrounds thesides of the combustion chamber,

a chamber or space outside of the bridge wall connecting with theexternal air and opening 3o at the contracted lower end of thecombustion chamber and inlets for the gas also opening at thelowercontracted end of the combustion chamber, substantially as set forth.

6. The combination in a regenerative furnace, of a combustion chambercontracted at its lower part, a bridge wall which entirely surrounds thesides of the combustion chamber, a chamber or space outside of thebridge wall connecting -with the external air and opening at thecontracted lower end of the combustion chamber, inlets for the gas alsoopening at the lower contracted end of the combustion chamber and achamber outside of the said air chamber connecting with the upper end ofthe combustion chamber adapted to convey the products of combustion fromit to the stack, substantially asset forth.

Signed at New York, in the county of New York and State of New York,this 16th day of November, A. D. 1892.

` MARTIN WANNER.

Vitnesses:

PHILLIPS ABBOTT, M. L. FERRES.

